arch/arm/plat-iop/gpio.c

   1 /*
   2  * arch/arm/plat-iop/gpio.c
   3  * GPIO handling for Intel IOP3xx processors.
   4  *
   5  * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or (at
  10  * your option) any later version.
  11  */
  12
  13 #include <linux/device.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/errno.h>
  17 #include <linux/gpio.h>
  18 #include <linux/export.h>
  19 #include <asm/hardware/iop3xx.h>
  20 #include <mach/gpio.h>
  21
  22 void gpio_line_config(int line, int direction)
  23 {
  24         unsigned long flags;
  25
  26         local_irq_save(flags);
  27         if (direction == GPIO_IN) {
  28                 *IOP3XX_GPOE |= 1 << line;
  29         } else if (direction == GPIO_OUT) {
  30                 *IOP3XX_GPOE &= ~(1 << line);
  31         }
  32         local_irq_restore(flags);
  33 }
  34 EXPORT_SYMBOL(gpio_line_config);
  35
  36 int gpio_line_get(int line)
  37 {
  38         return !!(*IOP3XX_GPID & (1 << line));
  39 }
  40 EXPORT_SYMBOL(gpio_line_get);
  41
  42 void gpio_line_set(int line, int value)
  43 {
  44         unsigned long flags;
  45
  46         local_irq_save(flags);
  47         if (value == GPIO_LOW) {
  48                 *IOP3XX_GPOD &= ~(1 << line);
  49         } else if (value == GPIO_HIGH) {
  50                 *IOP3XX_GPOD |= 1 << line;
  51         }
  52         local_irq_restore(flags);
  53 }
  54 EXPORT_SYMBOL(gpio_line_set);
  55
  56 static int iop3xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
  57 {
  58         gpio_line_config(gpio, GPIO_IN);
  59         return 0;
  60 }
  61
  62 static int iop3xx_gpio_direction_output(struct gpio_chip *chip, unsigned gpio, int level)
  63 {
  64         gpio_line_set(gpio, level);
  65         gpio_line_config(gpio, GPIO_OUT);
  66         return 0;
  67 }
  68
  69 static int iop3xx_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
  70 {
  71         return gpio_line_get(gpio);
  72 }
  73
  74 static void iop3xx_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value)
  75 {
  76         gpio_line_set(gpio, value);
  77 }
  78
  79 static struct gpio_chip iop3xx_chip = {
  80         .label                  = "iop3xx",
  81         .direction_input        = iop3xx_gpio_direction_input,
  82         .get                    = iop3xx_gpio_get_value,
  83         .direction_output       = iop3xx_gpio_direction_output,
  84         .set                    = iop3xx_gpio_set_value,
  85         .base                   = 0,
  86         .ngpio                  = IOP3XX_N_GPIOS,
  87 };
  88
  89 static int __init iop3xx_gpio_setup(void)
  90 {
  91         return gpiochip_add(&iop3xx_chip);
  92 }
  93 arch_initcall(iop3xx_gpio_setup);